The chair is very comfortable - I have spent hours straight in this chair and have no complaints about how it feels or how adjustable it is. You can raise/lower the total height of the chair with the gas cylinder's lever, the seat can recline it small increments to an angle that is so laid back you'll think you might tip over (but I didn't), the pillows are adjustable, and even the armrests are "4D adjustable" That means they can move up/down, left/right, forward/back, and they can be rotated clockwise/counterclockwise.
The first three adjustments for the armrests are all locked and can only be actuated by depressing a button first. But, the rotation is not locked out and I find that they rotate by accident quite often. For example, using the armrests to get up may make them rotate, and pushing the chair out of the way using the armrest as a handle may make them rotate. The armrests are also not upholstered and have a fairly thin rubbery surface for you to rest on. It is not uncomfortable, but to me the quality does not match the body of the chair. Like the hinge covers, I feel the armrests are executed to a lower standard than the bulk of the chair, and really could be so much nicer.
While I have done well to keep my likeness out of my own reviews for the past 15+ years, I suppose some selfies are useful for reviewing a chair. The main point is that I have 6'2" tall and about 225 pounds, and while I am not the biggest guy you will meet, there are plenty of places that I just don't physically fit into - at least not comfortably. I am very comfortable in the EwinRacing
Flash Series chair, and it definitely has plenty of room for even larger (taller and wider) users. I can easily find nice positions for the two pillows, and I do like that the armrests can be adjusted in so many planes. As you see me posing below as if I was gaming, know that I have dialed in the chair just to my liking and that I am definitely comfortable.
The next two shots are intended to show that if you needed the chair to go higher, it definitely can. I can honestly say it is rare that my feet don't touch the ground, unless I am sitting on a bar stool - but here my feet are a good two to three inches off the ground with the chair at full height! So, all the people over 6'6", I'd say the Flash Series chair may be a good choice for you!
Eventually, my sidekick got his turn in the chair, and I may not get it back now. At 4 feet and change and just over 50 pounds, he isn't maxing it out in any way, but he sures does like sitting it all the same! Looking good buddy!